Endemic Mimosa species can serve as mycorrhizal "resource islands" within semiarid communities of the Tehuacán-Cuicatlán Valley, Mexico

Abstract

This paper explores if Mimosa species (Fabaceae-Mimosoideae) can serve as arbuscular mycorrhizal (AM) and nutrient "resource islands" in six plant communities in the semiarid valley of Tehuacán-Cuicatlán, Mexico. Spatial heterogeneity related to the occurrence of Mimosa species results in temporal differences in AM-fungal spore numbers and soil nutrients. A higher number of AM-fungal spores were found in the soil below the canopies of six endemic Mimosa species than in the soil from non-vegetated areas. For four species, Mimosa adenantheroides, Mimosa calcicola, Mimosa luisana and Mimosa polyantha, the soil below their canopies had more AM-fungal spores than the soil in non-vegetated areas during the wet season than during the dry season. Two species, Mimosa lacerata and Mimosa texana var. filipes, however, had more spores under their canopies during the dry season than during the wet season. Although physical differences are present within and between sites, in general the soil below the canopies of Mimosa species had significantly higher nutrient levels than the soil from non-vegetated areas. Mimosa species thus form "resource islands" that are not only rich in nutrients but also in mycorrhizal propagules. Mimosa species can serve as mycorrhizal "resource islands" by directly affecting AM-fungal spore dynamics and/or by serving as spore-traps. A range of plants associated with Mimosa species may benefit from the higher number of AM propagules. We believe that the use of Mimosa resource islands as an option for biodiversity conservation and for land restoration ought to be considered in the Valley.

Abundance, richness and root colonization of arbuscular mycorrhizal fungi in natural and semi-natural land use types at upper Hantana

“…According to previous studies, AMF colonization by roots is influenced by several factors including soil properties, soil water content, plant phenology, predation and propagule availability (Anderson et al, 1984;Johnson et al, 1991;Anderson et al, 1994;Schultz et al, 2001;Muthukumar et al, 2003). Others suggested that AMF spore abundance do not always correlate with root colonization potential of AMF (Camargo-Ricalde and Dhilion 2003). In favour of the present findings, Daniell et al (2001) stressed that the level of spore production does not reflect the abundance of AMF in roots.…”

Effect of scarification and temperature on seed germination of two Mexican species of Mimosa (Leguminosae-Mimosoideae)

“…110 species, 60 % endemic to the country, many of them occurring as dominant or co-dominant elements in arid ecosystems, widely distributed in tropical vegetation, and few species growing in temperate forests (Grether et al, 1996;Camargo-Ricalde et al, 2002). Within arid and semi-arid environments, some Mimosa species are resource-island formers, enriching the soil with organic matter and nutrients (Camargo-Ricalde et al, 2002, 2010a, and as reservoirs of arbuscular mycorrhizal fungal spores (Camargo-Ricalde and Dhillion, 2003), and nitrogen-fi xing bacteria (CamargoRicalde et al, 2010a, b). In addition, the nurse effect is very clear between Mimosa luisana Brandegee and Neobuxbaumia tetetzo (F.A.…”

<i>Prosopis laevigata</i> and <i>Mimosa biuncifera</i> (Leguminosae), jointly influence plant diversity and soil fertility of a Mexican semiarid ecosystem.

“…Plants compete for water and nutrients, at the same time, they protect one another from extreme climates and provide additional resources by the incorporation of fresh litter for microbial activity, creating fertility islands (García-Moya & McKell 1970), or resource islands underneath their canopy (Reynolds et al 1999), which favors the establishment of plant communities (Perroni-Ventura et al 2006, López & Ortuño 2008. Keystone species are critical for these processes, because they have strongly influence on seed banks and seedling recruitment, even becoming the habitat of microorganisms, birds, rodents, and insects, whose role is critical for processes such as decomposition, spread, pollination, and plant establishment (ValienteBanuet & Ezcurra 1991, Camargo-Ricalde & Dhillion 2003, Wright et al 2006. These species frequently increase soil limiting resources and offer environmental conditions (i.e.…”

“…filipes (Britton & Rose) Barneby (Camargo-Ricalde et al 2002, Camargo-Ricalde et al 2010a. These species improve fertility and create resource islands, due to that modify of the micro-environmental conditions and function as reservoirs of soil nutrients, fungi spores and microorganisms under their canopies (Reynolds et al 1999, Camargo-Ricalde & Dhillion 2003, González-Ruiz et al 2008. For instance, arbuscular mycorrhizal fungi are critical to plant establishment, because they improve water and nutrients status of the host plant growing in arid regions (Tarafdar & Panwar 2008, Camargo-Ricalde et al 2010b.…”